I don't have the serial number in front of me, but it's a pretty generic question. My blade lift cylinders are "bouncy" both sides bounce like they have air in them when I stop moving the controls. It happens in both the up and down direction. I'm assuming that it's an internal seal problem with both cylinders, but before I take them off I was wondering if there's something else I should look at. Float position works as it should.
I would suggest checking the cylinder drift first. Get the hydraulic system oil up to normal operating temperature. Cycle the blade lift cylinders up/down a few times. Position the bottom edge of the blade about 10-12" off the ground and stop the engine. Note the measurement of the length of each lift cylinder rod that is exposed. Wait 5 minutes and measure again. Come back with your results.
There's nothing worse than a guy coming to look for help, then disappearing. I appreciate the feedback Nige and I'm sorry I didn't get back to this post quicker. We moved on to another job and have been busting our butts. I'll get back to that D5 here this week and will let you know what we find out.
Well, I'm back. My world is a busy mess. @Nige the blade does not leak down overnight. I'm going to try and post a video link to my YouTube channel. Looks to me that the lift cylinders need rebuilt, but both of them going bad at the same time has me wondering if it's something else. While the video only shows the right side cylinder, both bounce like this. If I load the blade on a push, I cannot lift it while traveling. I have to stop, back up a tiny bit, and the blade will lift.
I’m far from an expert but that looks like pump cavitation to me. I’d check for air in the system and why the pump is starving for oil.
I'm not sure on your machine but most dozer blade cylinders have quick drop valves in the cylinder pistons.........yes, they do fail.
Either that or they are mounted on top of the hard nose.
Neither apparently. There is a makeup valve in the blade lift section of the implement control valve. Look at #11 on the attachment.
All other hydraulics work fine and the hydraulic level is good. The blade cycles up and down smoothly, it only happens when you stop the blade direction quickly.
Thanks Nige. That is the kind of info I was looking for. I will look into it soon.
I really don't think you have a problem I believe what you are seeing is the tractor rocking and it being amplified by the blade being far from pivot point watch the dash in your video